A problem in the meat packing industry is the formation of metmyoglobin and growth of aerobic bacteria on finished packages of meat, reducing the shelf life of meat and ending in vast amounts of waste. Metmyoglobin is an oxygenated form of myoglobin, a protein in meat. The problem arises when the meat, in either ground or sliced form, is exposed to air for too long. Deoxymyoglobin is a precursor protein which when oxygenated forms oxymyoglobin in a normal atmosphere of oxygen. Oxymyoglobin is responsible for the bright red color of meat which is desirable. When oxymyoglobin is immersed in a substantially oxygen deficient atmosphere, the process reverses itself and the oxymyoglobin will reduce, yielding oxygen in gas form or dissolved in the surface water of the meat. If the free gas space in the package is very small, such as a chubb package, or even a vacuum package, the relative percentage volume of oxygen can become very high. This can lead to metmyoglobin formation, discoloration and growth of aerobic bacteria in the areas of high oxygen concentration.
Previous methods of controlled atmosphere or modified atmosphere packaging have sought to eliminate oxygen in packages, however, not realizing the detrimental effect that oxygen trapped in the form of oxymyoglobin can have, once packaged. Bright red meat, full of oxymyoglobin, packaged in low oxygen will inevitably result in the worst looking meat. Attempts to deal with this included using oversized packages with excess amounts of free space in the package. Further, methods of processing beef are beset with other inefficiencies and problems.
For example, typically all carcasses are chilled prior to further processing, yet the carcasses contain a great deal of bone and other materials that are not used for human consumption and yet the entire carcass is chilled prior to processing. Furthermore, the shape of meat primals made into food items used for human consumption are of irregular and inconvenient profile. Conversely, packaging trays that have been cost effectively and efficiently manufactured, are invariably rectangular and/or square in profile. By adopting procedures disclosed herein, it will be seen that costs of chilling are reduced since, for example, the skeleton can be removed before chilling thereby saving costs of such chilling process. Fresh red meat tissue is typically quite soft and easy to cut immediately after the animal has been slaughtered and prior to the natural, “hardening” effects of rigor mortis has occurred. It can therefore be easier and quicker to cut primal portions from animal carcasses, during the normal animal “disassembly” process prior to rigor mortis and chilling. Those fresh red meat primal items, that are intended for human consumption, can then be shaped by placing into molds of a specifically designed and desired profile prior to rigor mortis and then chilled during the natural rigor mortis process. This device will provide a method to change and adjust the shape of fresh red meat primal items so that, for example, fresh red meat primal items can be readily and automatically processed during the slicing and cutting process as required prior to packaging. Furthermore, profiles of primal meat portions can be fixed so as to be more convenient when slices of fresh red meat primal items are loaded into improved packaging, such that packaging volume can be efficiently utilized, while still maintaining a space efficient, appealing and attractive appearance for the consumer at the point of retail display and/or food service outlet.
Typical modified atmosphere packages for fresh foods, such as red meats and other perishable foods, have a limited shelf life, and typically include a thermoformed tray or other package composed of EPS/tie/PE (barrier foam trays) plastics material or other suitable substantially gas impermeable material, i.e., tray, overlaid with a single transparent web of plastics material that can be heat sealed to the tray. A typical substantially gas impermeable heat scalable composite web includes a biaxially oriented polyester (PET) layer/tie layer/gas barrier layer (such as PVDC) an adhesive layer/heat sealing layer (such as polyethylene), which in turn is finally adhered by a heat sealer to the tray. The polyethylene layer is a heat sealable layer that is tied to a gas barrier layer such as polyvinylidene chloride which is in turn adhered to polyester. Because of the diverse types of materials that are employed in the foregoing package, it is difficult to reprocess and recycle the post-consumer package. Moreover, the cost associated with post-consumer recycling of multiple layer plastics material renders the process impractical and substantially not economically feasible.
Commonly used modified atmosphere packages for fresh foods such as red meats and other perishable foods having a limited shelf life typically comprise a tray thermoformed from a sheet of EPS (expanded polystyrene) laminated to a web of substantially gas impermeable web material or other suitable substantially gas impermeable material. A lid, such as a single or composite transparent web of plastics material that can be bonded to the flanges of the tray. Both tray and lid materials are typically substantially gas impermeable heat sealable composite structures and cannot be readily recycled. Lid material typically comprises a laminated structure including several layers such as bi-axially oriented polyester bonded to a gas barrier layer (such as PVDC) which is sandwiched between an adhesive or heat sealing layer (such as polyethylene). Because of the diverse types of materials that are employed in the foregoing package, it is difficult to reprocess and recycle the “post-consumer” package. Moreover, the cost associated with post-consumer recycling of multiple layer plastics material, such as the aforementioned, renders the process impractical and substantially not economically feasible.
A further limitation of packaging perishable goods such as fresh red meats in hermetically sealed gas barrier packages results from the need to enclose a relatively large volume of gas, within the package. Clearly, consumers have no interest in purchasing these gasses that accompany the red meat. Minimizing the size and bulky appearance of such packaging is desirable. Additionally, a major proportion of red meat production occurs at locations that are located at a substantial distance from the point of retail sale of red meats to consumers. Most U.S. beef is produced in the central plains around Kansas, Nebraska and Iowa and the major markets are situated on the coastal regions such as New York or California. Costs of shipping these fresh red meat items from the point of production and packaging can be reduced if the packages are reduced in volume. However, reduction in the volume of gases provided within a package can have a deleterious effect on shelf life of the perishable goods and red meat contained therein as explained above.
The packaging industry has therefore felt the need for simplified individual packaging structures that will provide finished package performance including label requirements for a variety of applications. Additionally, if the packaging can be handled economically both in the pre-consumer handling and in post-consumer recycling, significant economic advantages are available.
With conventional packaging of meats and other perishable type goods, the shelf life is limited due to bacterial growth within the package. The growth can be inhibited when the package contains carbon dioxide gas, however, carbon dioxide will dissolve in liquids such as water contained within the goods in the package. After time, carbon dioxide can become substantially dissolved in the water, limiting the shelf life. When carbon dioxide dissolves into liquids and water, this can cause the package to collapse inwardly. Collapsing causes the appearance of the package to be unacceptable to consumers and can also cause the package to rupture.
In order to extend shelf and storage life of the packaged goods several inventions have been disclosed and examples of known packaging for this purpose are given in the following U.S. patents:
5,779,832KocherMethod and Apparatus for making a peelable film5,629,060GarwoodPackaging with Peelable Lid5,560,182GarwoodPackaging Method5,534,282GarwoodPacking Perishable Goods5,514,392GarwoodPackaging for Perishable Goods5,323,590GarwoodMethod of producing food packaging with gas be-tween tensioned film and lid5,226,531GarwoodFood Packaging with gas between tensionedfilm and Lid5,155,974GarwoodFood Packaging with gas between tensionedfilm and Lid5,115,624GarwoodThermoplastic skin packing means5,129,512GarwoodPackaging
The subject matter of the above patents is hereby incorporated by reference.
Prior art as described in U.S. Pat. No. 5,779,832 to Kocher, discloses a method of making a multilayer peelable film. Kocher discloses a method of co-extruding two webs of material simultaneously in the form of a multilayer film that can be delaminated into a third web and a second web and then, after treating the second web to improve gas permeability therethrough, re-laminating the third and second webs together. These two re-laminated webs can be sealed to a first web of gas barrier material and thereby produce a package. The first web may have a depression formed therein into which goods such as red meat can be placed before heat sealing the third and second webs to the first web. Typically, goods will not completely fill the depression and space will remain in the depression in addition to the goods. A blend of gases or a single gas such as CO2 can be provided in the space with the goods and thereby can contact the goods. After storage and prior to retail display at an intended point of sale to consumers, the third web can be peeled from the package allowing atmospheric oxygen to permeate the second web of gas permeable material and to contact the goods. The atmospheric oxygen can then allow generation of a bright red colored substance such as oxymyoglobin thereby providing an appearance attractive to the consumers.
It has been found that when applying the second and third webs extruded in the manner as disclosed in Kocher to packaging as that disclosed in the inventor's own U.S. Pat. No. 5,534,282, a dull appearance of the second web can result with reduced clarity when compared with other webs of material that are produced in a single web such as plasticized PVC (pPVC). Furthermore, after removal of the third web, from the re-laminated co-extrusion, by peeling, as described in U.S. Pat. No. 5,534,282, distortions and ripples can appear in the second web. This occurs, partly, as a result of inadequate lateral tension provided in the second web when limited by the inherent limitations of co-extruding the second and third webs simultaneously. This can, therefore, severely detract from the visual appearance of the package in the eyes of consumers.
Conventional modified atmosphere “case ready” retail packaged fresh red meats and other perishable type goods experience limited shelf life because of bacterial growth, such as aerobic and anaerobic bacteria, on the packaged goods; rancidity “off flavors” caused, in part, by oxidizing fats; and discoloration to visible meat surfaces. The growth can be inhibited when goods are treated by exposure to certain agents prior to packaging and then providing certain gases and/or other agents with the goods within the finished and sealed package. However, some gases such as carbon dioxide gas, for example, can quickly dissolve in substances such as oils and water contained in the goods. After time, carbon dioxide can become substantially dissolved in water which may limit shelf life. Furthermore, when oxygen is present and more particularly when a quantity of approximately 5,000 to 30,000 parts per million of oxygen is present in a gas within a package, discoloration due to formation of metmyoglobin on the visible surface of red meat, reduces consumer appeal of the packaged goods. When carbon dioxide dissolves (into another substance) the combined volume of the residual substances is substantially reduced which can cause the package to collapse inwardly. Collapsing causes the appearance of the package to be unacceptable to consumers and can also cause the package to rupture and render it unfit for use. In compensating for such a deleterious event, several existing packaging systems require large volumes of gas to be packaged with the goods. However, when large volumes of gas are provided, the resultant “bulky” condition does not provide for cost efficient shipping and distribution from the location of packaging to the point of retail sale of the packaged goods.
Conventional packages for red meat are produced in one or more sizes. When packaging red meats or other perishable goods, the package must conform to the goods. Therefore, if a red meat portion is too large for one size of a package, the next larger size must be used. Oftentimes, this will lead to an overly large sized package introducing inefficiency into the process because of the wasted space. In order to maximize efficient use of the internal space available in a typical road, rail or sea, refrigerated shipping container or trailer, it is important to increase the density and unit weight per unit volume of the packaged perishable goods. The maximized efficient use of the space in the shipping containers can be achieved by adjusting the shape of the inconveniently shaped animal fresh red meat primal portions such that slices of the fresh red meat primal portions will fit and substantially fill the available space within trays of the improved packaging.
High oxygen case ready packages are inefficient, in large part, due to the inherent need to include a quantity/volume of gas that is equal to, or greater than the volume of the package meat contents. For example, a high oxygen package comprising a barrier foam tray and clear barrier film lid, hermetically sealed to flanges of the barrier foam tray and with a 2 lb. quantity of meat sealed therein will require approximately 1 liter of gas to be enclosed and sealed within the package to ensure that an approximate 10 day shelf life extension can be provided. Said gas (referred to as modified atmosphere) will typically comprise 80% Oxygen and 20% Carbon Dioxide but other combinations that may include relatively small quantities (say <10%) of residual atmospheric nitrogen are also typical. The relatively high level of CO2 (when compared to ambient atmosphere) is provided to inhibit bacterial growth, and with good storage temperature control, a shelf life for ground, fresh meat can be extended to over 10 days from packaging. The bacterial controlling effect is a consequence, in part, of a characteristic of bacteria entering a “lag phase” when the environment in which it is placed, significantly changes. Eventually, the bacteria will adapt to the atmosphere that is present and commence normal, reproduction and extended infection. The shelf life extension will vary according to several factors including, for example, the following storage temperature, i.e., the less variation from a minimum temperature of approximately 29.5° F. is optimum, (while ensuring that freezing of the meat, which occurs at about 26–27° F., does not occur); the condition and age of the meat at packaging, the conditions at the point of packaging such as hygiene, temperature etc., muscle type and age of animal from which the meat was harvested. Nevertheless, a shelf life extension of 10 days is readily reproducible when conditions are maintained as required. After a relatively short period of time, the CO2 provided within the package will dissolve into the water and oils contained in the meat and the oxygen is present to ensure that a consumer appealing/acceptable “bloom” or “redness” is maintained. The “bloom” is caused by the natural color of oxymyoglobin and oxyhemoglobin that is present in freshly cut meat but when oxygen is present, after approximately 9 to 10 days discoloration such as browning due to increased levels of surface metmyoglobin will occur, rendering the product unsalable or requiring a reduction in price to sell to a consumer. Furthermore, the excessive volume of the finished packages, results in excessive packaging material and shipping costs and display case space at retail outlets and also excessive costs incurred for disposal of additional cardboard, etc., at the supermarket outlets.
Effective packaging materials for existing, extended shelf life, retail packaged, case ready perishable goods are often relatively expensive and the associated packaging processes are typically labor intensive. The use of EPS and FP can provide desirable low cost packaging materials but the inherent cell structure of these materials can retain residual oxygen (from air) within the cell structure, even during and after exposure to very low levels of air pressure (vacuum). When EPS and FP materials are used in low residual oxygen modified atmosphere packaging, such as described in U.S. patent application Ser. No. 09/039,150, residual oxygen can diffuse and exchange from the cell structure, and become present as a free gas within the master container thereby elevating the level of oxygen present therein to a potentially undesirable level. As described in the subject matter of U.S. patent applications in the name of the present inventor, apparatus for minimizing the level of residual oxygen retained in the cell structure and master containers are disclosed. However, such a process of gas exchange is problematic and difficult to reliably maintain. Therefore, packaging fabricated from solid plastics sheet, may be more efficiently employed in this present application.
Conventional “master container” or “master package” modified atmosphere packaging (MAP) systems include loading perishable goods into trays and then a plurality of loaded trays are subsequently placed into a larger “master container” which may be manufactured from a suitable gas barrier material. The “master container” is typically evacuated of air and then filled with a gas blend that may include a mixture of any desirable gases which may include, for example, 40% carbon dioxide and 60% nitrogen for a low oxygen MAP system. The master container is then sealed with loaded trays to provide an airtight, sealed master container, containing loaded trays and a gas blend with a residual quantity of atmospheric oxygen. Most desirably, for low oxygen MAP systems, the residual quantity of atmospheric oxygen will not exceed an amount of 100 to 300 PPM (parts per million) with the balance of the gas blend including nitrogen and carbon dioxide and/or other inert or oxygen free gases. Low cost packaging materials include foamed polystyrene (EPS trays), however, the choice of material for tray manufacture must exclude materials (unless treated in a manner that will substantially remove atmospheric oxygen from the cell structure), such as expanded (foamed) polystyrene (EPS), that have a capacity to “retain” air, even after exposure to a high vacuum as may occur in packaging processes. Therefore, in order to maintain the residual quantity of atmospheric oxygen at not more than 100 PPM, untreated expanded (foamed) polystyrene (EPS) or FP trays cannot be easily and efficiently used. By way of explanation, EPS trays are typically thermoformed from extruded EPS sheets. A typical method of producing an EPS sheet is to “foam” the melted (liquid) polystyrene by injection of a foaming agent, such as nitrogen, carbon dioxide or pentane, into liquid polystyrene thereby causing it to foam (become frothy, with bubbles and/or tiny gas filled cells within the foam) and then extrude the foam through a slot in a flat or annular die. The extruded EPS can then cool and solidify into a sheet that can be slit and wound onto a roll prior to further processing. Immediately after extrusion of the EPS sheet, cells retained within the foam are filled with nitrogen or other gas (foaming agent) used in the foaming process. However, such a foaming agent gas, if not retained by other means in the cell structure, can quickly exchange with the ambient air during storage and the cells can become filled with air. When placed within a vacuum chamber and exposed to a high level of vacuum, as is normal in a “master container “packaging process for low oxygen MAP systems, cells can retain a quantity of air, even during and subsequent to evacuation (unless the exposure to vacuum is significantly extended to the extent required). The retained quantity of air in the cells, can subsequently exchange with gas within the sealed “master container” which can, thereby, elevate the residual oxygen content of the “free” gas contained within the “master container” above a desirable level.
A fundamental need that resulted in the development of thermoformed EPS trays initially arose in the modem supermarket. Fresh meats and poultry were processed and retail packaged at the supermarket immediately prior to retail display and sale. EPS foam trays were developed to meet these supermarket requirements, and have provided a functional and low cost retail package, when “over wrapped” with, a low cost web of plastic material such as plasticized PVC. However, with case ready MAP systems, such EPS trays are now required to be shipped in trucks and other means of transport from the point of packaging, which may be located many hundreds of miles from the point of sale. Abuse and damage can occur to the packaging during this shipping. In an effort to protect against damage, rigid and heavy weight cartons with sheets, cushions' and/or columns, made from suitable materials such as chipboard are manufactured and assembled with EPS trays and goods contained therein. Such protective packaging is expensive, bulky and results in excessive shipping costs. Furthermore, excessive packaging, as required for the sole purpose of protection during shipping, must be discarded at the supermarket thereby creating excessive waste disposal problems with the attendant costs to the environment. It would therefore be desirable to produce rigid packages and containers that can withstand the abuse of long transportation routes.
Typically meat packing companies slaughter cattle and then process the dressed carcass by chilling and then disassembling the carcass into portions of meat which can then be, in part, delivered to the point of sale to consumers, in vacuum packs. However, approximately 40% of the disassembled meat is processed by coarse grinding and then blended to provide ground meat with a selected with a selected fat and lean content as required by the retailer. The fat and muscle content of the ground meat may be, for example, 20% fat and 80% lean. Typical current processing methods require that the boneless meat be firstly coarse ground then blended, vacuum packaged, delivered to a supermarket or packaging facility close to the consumer where the coarse ground meat is fine ground and then retail packaged immediately prior to retail display. This conventional process inherently results in excessive exposure of the ground meat to ambient atmosphere including oxygen during the grinding and blending process at the point of slaughter. Furthermore, this process requires that relatively large quantities of ground beef are blended together in a single batch. Because it is not possible to disassemble a carcass and provide boneless meat therefrom with a precise and selected ratio of fat to muscle tissue, the typical batch blending process often requires several attempts to produce the desired ratio of fat to lean content. The general industry practice is to deposit selected boneless beef with a fat to lean ratio as close to a desired tolerance as possible. The selected boneless beef may have a fat to lean ratio of 15% fat to 85% lean +/−5%. Typically, a sample of the blended boneless beef is then removed from the blender and then can be tested to determine fat and lean content using, for example, a device known as an Analray testing procedure. After determining the fat and muscle content of the coarse ground meat, additional fat or lean meat is added to the batch blender and the full batch is again blended for a period of time and then a second sample is extracted and tested to determine fat and lean content. If the fat and lean content is as required at this point, the batch of coarse ground meat can be vacuum packaged and stored in refrigerated facilities prior to delivery to the point of retail sale. However if the fat and lean content is not as required, then, additional fat or lean meat can be added to the batch and further mixing is then required. This process is often repeated as many as 5 times or more. Each time the coarse ground meat is blended again it is damaged by the blending process. This damage may include “fat smear” or over heating. Heat is generated during this blending process and “fat smear” occurs when the meat has been exposed to excessive blending. This procedure is expensive in terms of energy, labor and equipment time. Furthermore, damage to the ground meat is undesirable and yet damage typically occurs as a matter of normal process with the currently predominant industry procedures. During the process described above the meat is exposed to ambient air and bacteria such as E. coli 0157:H7 and other dangerous bacteria can be present in the blended ground meats. Excessive blending can cause the bacteria to spread throughout the batch of meat in the blender.
Ground meat such as ground beef is produced by processing selected portions of boneless meat, including fat and muscle tissues, through a grinding machine. The relative quantities of fat and muscle contained in any batch of the portions of boneless meat is typically arranged to correspond with set industry standards. The batch of boneless meat may include about 93% muscle tissue and therefore the balance of about 7% would be fat. The following TABLE 1 of items 1 to 5, shows the fat and muscle tissue content of some typical industry specifications for boneless meat:
TABLE 1MuscleItemTissueFat Tissue193%7%290%10%375%25%465%35%550%50%
Although the industry standards are established, it is difficult to produce large quantity of boneless beef to any specification or ratio of fat and muscle. This difficulty can arise as a result of genetic variation in the animals from which the boneless meat is harvested. Consequently, there is often variations that could be as much as +/−2% to 3%, which corresponds to a possible variation of up to 6% and perhaps even more, in the actual fat or muscle content of the boneless meat.
Typically, consumers can purchase fine ground beef with a fat content that is specified and clearly marked on any retail package. The fat content may be specified to 10%, 25%, or 30% and it is illegal, in several U.S. states, such as California and New York, to sell such retail products to consumers if the fat content is higher than the amount shown on the retail package. Therefore, producing retail packages of ground beef with a fat content of, for example, 25%, may be achieved by grinding a known quantity of Item 2 (listed above) and blending this with a known, measured and corresponding quantity of Item 4 (listed above). The fat content of the resulting ground beef can be measured but it is common for the fat content variation in the initial quantity of the boneless beef items to vary to such an extent that a compensating procedure must be accommodated during production of the product for retail packaging. This compensating procedure can often result in production of ground beef that has a muscle content that is higher than is specified on the retail package. The consumer, however, only pays for the ground beef according to the fat content shown on the retail package. Thus a loss of profit for the ground beef producer can be incurred.
Typically, a quantity of boneless beef, with a specified muscle and fat content, for example, Item 5, is loaded into a hopper which is connected directly to a primary meat grinder. The portions of meat are progressively carried, by augers and compressed into a tubular line with a perforated grinding plate fitted across. The grinding plate is typically manufactured from suitably hardened steal and the perforations may include drilled and reamed holes of a chosen diameter, which may be about 0.5″ diameter, and which extend completely through the grinding plate. The primary grinder typically produces coarse grinds with the diameter of the meat pieces corresponding with the diameter of the drilled and reamed holes in the grinding plate.
After primary grinding a quantity of Item 5 may be blended with a selected quantity of coarse ground Item 4. After the blending of Item 5 with Item 4 the resultant mix is processed through a secondary fine grinding machine prior to portioning and retail packaging. The secondary fine grinding machine may be similar to the primary coarse grinding machine except that the grinding plate can be drilled and reamed with holes of less than about 0.25″ diameter.
Typical fine ground meat for retail packaging and sale to consumers may be produced with fat and muscle content as shown in the following TABLE 2:
TABLE 2MuscleItemTissueFat Tissue1F90%10%2F75%25%3F65%35%
The existing grinding, blending and processing equipment, such as that made by the Weiler/Beehive Company, has been demonstrated as effective for grinding meats of various types. However, little has been proposed to improve the quality of the ground meats by, for example, arranging equipment in such a manner so as to substantially prevent contact of the ground meats with air and/or atmospheric oxygen during the grinding and blending processes. The conventional equipment does not allow for continuously and automatically grinding, measuring and blending the ground meats in such a manner so as to continuously produce quantities of ground meats to an exact and predetermined muscle and fat content. In particular, nothing has been proposed in the way of automatically controlling the fat content.
The present invention provides methods, systems and apparatus to automatically and continuously grind, condition, blend, treat and package the ground meat products with improved accuracy of muscle tissue to fat tissue ratio, so as to minimize losses to the processor. The ground meat can then be packaged in suitable packaging that will enhance the keeping qualities of the products and provide a safer effective method of delivering the goods to consumers.
Bovine Spongiform Encephalophathy (BSE) is an incurable disease, that can “jump” from cows to humans, and is considered (albeit low) a threat to the US beef industry. It has been, typically, contracted by cattle as a consequence of the animal eating “blood & bone meal” that has been used as a component of the animal's feed where the “blood and Bone” meal has been derived from a cow that has BSE. The practice of feeding “blood & bone” to cattle in their feed is now illegal in the USA and many other countries but there is still a risk of the disease being imported from a country that still allows this practice. Furthermore, a cow can become infected by eating as little as 1 gram of contaminated meal. BSE has been reported in 18 countries and is a threat to the US beef industry. BSE is not believed to be contagious and can only be contracted in humans by consuming of a part of the cow. “Foot and Mouth” or “Hoof and Mouth” is also another threat to the US beef industry and all other cloven foot animals.
Some one billion lbs. of boneless beef is imported from Australia and New Zealand, into the USA annually. US Federal legislation may someday dictate the requirement to display information on the retail pack to consumers and show the country of origin as well as all other details as, among other things, a guard against illegal imports from banned source countries such as China.
Global Animal Management (GAM) is a company owned by Schering Plough that has established a system and large computer data-base that is intended to record all information about a beef animal from birth to slaughter. Unfortunately, the value of this information is lost at all US slaughtering plants because they cannot trace the animal through the packing plant disassembly process.